The tube plate of a creel for a cheese-producing textile machine is generally used to center the cheese tube within the creel and to assist the holding of the cheese tube by tension against the creel arm as the cheese is formed by winding yarn about the tube. Various conventional tube plates are known and described in the prior art.
For example, a tube plate as shown and described in German Patent No. DE 43 43 866 A1 comprises a cylindrical centering attachment whose greatest outside diameter is somewhat smaller than the smallest inside diameter of the tube. The cheese tube is fixed in the creel substantially via its lateral edges between radially projecting contact surfaces of the tube plate. That is, there is generally a little play between the inside diameter of the tube and the outside diameter of the centering attachment of the tube plate.
This tolerance-conditioned play between tube plate and tube does have advantages if, as described in German Published Patent Application No. DE 101 39 072.6, a new yarn is to be fixed between the tube plate and a lateral edge of the tube during the restarting of spinning at a workstation and the tube plate is slightly tilted so that, using a so-called tube-plate opener of a service unit, a yarn strand can be fixed in the resulting slot. However, such tube plates, because they are supported in an oscillating manner, also have some not insignificant disadvantages that become evident during the winding process.
During the winding process, for example, the tube plate rotates constantly relative to the tube, which results in, among other things, a distinct wearing of the tube plate and, occasionally, the fixed yarn wearing through, with the possible consequence that the yarn reserve unwinds. Moreover, the play between tube and tube plate hinders the transmission of bobbin oscillations onto the creel, which oscillations are then often defectively absorbed by the oscillation damper of the creel, creating bobbins of a poorer quality.
Play between the tube and the centering attachment of the tube plate also has a particularly negative effect in the production of cheeses wherein the exact bobbin speed must be ascertained, such as in stepped precision winding, wherein the quality of the yarn package is determined by the performance of the winding head computer. The bobbin speed can be determined rather simply using a Hall effect sensor on the creel and one or several magnets on the tube plate, provided, however, that the tube plate rotates exactly at the speed of the bobbin. This condition requires that there be no slip between the tube plate and the cheese tube.
The disadvantages described above can be avoided to a great extent by using a tube plate like the one described, for example, in German Patent No. DE 38 37 337 C2. This tube plate comprises conical tube receptacles whose large outside diameter is distinctly larger than the inside diameter of the tubes. In such an arrangement the tube is centered and fixed directly by the conical tube receptacles.
However, such tube plates are disadvantageous when a spinning restart is to be made at a workstation according to the method described in German Published Patent Application No. DE 101 39 072.6. These known tube plates are particularly unsuitable for fixing the new yarn between the lateral edge of the tube and between the tube plate since such a tube plate, when it is designed for an oscillating motion and is tilted in order to allow the yarn end to be clamped, is subsequently no longer securely aligned with the axis of rotation of the tube. Rather, such a tube plate results subsequently in a wobbling motion when winding on a yarn. Therefore, the tube plates according to German Patent No. DE 38 37 337 C2 have spiral grooves for fixing a new yarn, which grooves, in theory, draw the yarn under the tube and fix it there. However, this method is unreliable in practice.